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Quick guide: the small HVAC components for your design

clock 15 minutes | 18 Dec 2020

One of the challenges facing HVAC manufacturers and design engineers is how to create a more energy-efficient HVAC. Saving the customer money is only a small part of the equation – the HVAC needs to lessen its impact on the environment.

HVAC parts in your design aren’t limited to major components. The small HVAC components play a critical part in keeping your design performing at optimum level, delivering your desired efficiency.

But they all work together, so you need to know what each part is.

What about small HVAC unit components?

We’ve put together this guide to show you the unsung heroes you’ll need to consider – in other words, the small but vital HVAC system components. Keep in mind that there are so many different styles and types of HVAC systems for commercial buildings, as well as residential, so this is a general guide. If you’re designing industrial HVAC systems for manufacturing and warehouses, you’ll need to take into account the type of stock on site. Some stock will have particular needs when it comes to ventilation and air conditioning. It all boils down to understanding the space you’re designing for.

Free samples and CAD downleads

To make your job easier, we’ve made available free samples on most of our solutions, so you can try before you buy. You can also download free CADs of our solutions to help with designing your project.

What are the main components of an HVAC system?

HVAC system

The HVAC major components include:

Furnace: There are different HVAC types, as the furnace illustrates. It generates the heat and is typically gas, oil or electric. A combustion, also called a burner, chamber ignites the gas or oil, both of which come from a supply line. Electric furnaces use a heating element to heat the air. Industrial heating elements aren’t very efficient, but the flip side is, they don’t involve fumes from burning, as is found with gas and oil.

Ducts: Usually made of aluminum, HVAC duct components are both heating and air parts, even though positioned outside of your HVAC. They carry heated or cool air to vents in the building, where the air is released. Ducts can run through the floor, walls and even the ceiling. Supply-line ducts carry the air into the building while the return line sends air back to the furnace, where it can be heated or cooled again.

Heat exchanger: This is another one of your heating-system parts. All three furnace types have an exchanger. It’s heated by either combusted fuels or if an electric furnace, the heating element. Air is either blown from outside or by the return duct through the exchanger, which heats the air.

Blower motor: The component that blows conditioned air from the furnace, heat pump, or air conditioner through the ducts and into the home or building.

Air filters: The process of exchanging air is part of the ventilation system. This means air filters and ducts can be considered ventilation parts. The warm or cool air returned back to the furnace to be reused is cleaned by the filters, which remove dust and other particles.

Condenser: Components of an air-conditioning system include the condenser. A refrigerant chemical circulates through the system, turning into gas, where it is received by the condenser and cooled. It then turns into liquid again and flows back through the refrigerant lines inside the building, and then to the evaporator coil. It’s there that cold air is produced.

Evaporator Coil: This is located inside a metal box, typically outside of the furnace and is sometimes called a furnace coil. Standard AC parts also include a blower which, as the name implies, blows hot air in, usually from the return duct. The refrigerant sent to the evaporator coil dissipates in the heat, cooling the air. This is then blown through the ducts and through the building. Meanwhile, the refrigerant flows back to the condenser for cooling again.

Thermostat: Both heating and AC system components rely on the thermostat to maintain a comfortable temperature. Most thermostats nowadays are digital, but electric or mechanical options are still common. The thermostat reads the temperature of the air, then signals to the reading to the rest of the system so that it acts accordingly, either heating, cooling or keeping the temperature as it is.

These new furnaces should be accompanied by a matching thermostat in order to take advantage of these variable heating and distribution outputs.

Small HVAC unit components

Now let’s look at the small components key to enabling the HVAC to function:

Thermostat and control panel

HVAC thermostat and control panel

Thermostat and control panel

These are the heart of HVACs, so we’re going to start here. The other major components need to be wired to take instructions from thermostats and control panels, so you need to think about PCB hardware components.

​Non-threaded spacer – ceramic

Non-threaded spacer – ceramic

Ceramic spacers installed by hand without the need for assembly equipment. Operating temperature range of -40°C to 1,700°C.

​PCB support pillars

PCB support pillars

These are thin, flexible PCB spacers that snap and lock. They can be flexed back after the PCB is installed for maintenance or repair. Use as a locking arrowhead or locking bayonet, depending on the hole. Nylon 6/6. Rated UL94 V-2. Operating temperature range: -40˚C to 85˚C.

​Transistor insulators

Transistor insulators

Transistor insulator pads provide low resistance to heat transfer while acting as electrical insulation between the power device and metal parts.

PCB spacers – non-threaded/round/through

PCB spacers – non-threaded/round/through

These non-threaded, round spacers are installed by hand without the need for assembly equipment. Available in several different materials, including nylon 6/6, in a wide array of sizes.

​Fan filter sets

Fan filter sets

Fan filter sets include one each of fan guard to protect fingers, fan filter cover, fan filter mesh sheet and felt filter. IP30 rated for protection from tools and wires greater than 2.5mm.

​LED lens holders

LED lens holders

LED lens covers for HVAC control panels using LED lights. Designed to hold a standard T-1 3/4 LED while transmitting light at a 10˚ angle. Available with or without a sealing o-ring and made of strong polycarbonate. Operating temperature range: -40˚C to 130˚C.

HVAC furnace


If your furnace will have a thermostat to link with another one on a control panel, see the Thermostat and control panel section above.

​Stainless-steel cable ties

Stainless-steel cable ties

For industrial HVAC solutions, 316 stainless-steel cable ties are ideal, providing strength and durability. Ties are self-locking and easily installed by hand. Resistant to extreme temperatures. Also good for the blower.

​Cable tie gun – stainless steel ties

Cable tie gun – stainless steel ties

Makes installation of cable ties quick and easy. Squeeze the two handles together to cause the tie to loop together and give tensile strength to the tie, creating a secure fastening around your cables.

​Aluminium P-clamps for cables

Aluminium P-clamps for cables

Ideal for securing, grounding and routing cables. Available for bundles from 3.2mm – 31.8mm and mount securely with a #10/M5 screw or other fastener. You can also get this style as a nylon cable clamp in UL94 V-2 and UL94 V-0 rated materials.

​Cable strap – nylon roll

Cable strap – nylon roll

A two-part cable management solution with a locking button that offers high degrees of flexibility. Available in elastomer or black nylon 6/6, you can wrap and secure cables to bundle them together. UL94 HB.

HVAC ducts


HVAC duct system components should include solutions designed to make supporting the ducts easy.

​Self-drilling and self-piercing screws – pan head

Self-drilling and self-piercing screws – pan head

Pan head self-drilling screw with a pointed head style enables the screw to self-tap into a panel, speeding up the assembly of duct fittings and making the process fast and easy. Made of cost-effective mild steel.

Cable tie gun

Cable tie gun

Suited for cable ties with widths up to 10.0mm, enabling the installer to tighten the tie around cable bundles quickly and in one movement.

HVAC Heat Exchanger

Heat Exchanger

You’ll need to consider the maximum operating temperature for components in your heat exchanger compartment. A furnace heat exchanger can reach 170˚F.

​Braided cable sleeve

Braided cable sleeve

Protect cables and wires from damage while providing cushioning from vibrations. Braided cable sleeves stand up to dissipating heat and moisture. Available in different materials, including nylon 6/6 with an operating range of -60˚C to 160˚C and polyester, with an operating temperature range of -50˚C to 150˚C.

​Cable wrap – spiral

Cable wrap – spiral

Spiral cable wrap is a lightweight and protective wrap that provides cost-effective hose and cable protection. If using for cables, you can route them at any point from the bundle to a different direction, keeping the space organised and clear. Available in heat-stabilised nylon with an operating temperature range of -50˚C to 150˚C and polyethylene and LDPE, -40˚C to 85˚C.

​Heat-stabilised nylon cable ties

Heat-stabilised nylon cable ties

Ideal for areas, such as the heat exchanger, where heat is generated or present. Nylon 6/6. Rated UL94 V-2 with an operating temperature range of -40˚C to 200˚C.

​Side pull plugs

Side pull plugs

Protect open ports from contamination and damage during shipping and storage with caps and plugs. From centre-pull plugs to snap-fit plugs, Essentra offers a full range of protection solutions. Also ideal for condensers.

HVAC blower motor

Blower motor

Any HVAC equipment that turns is prone to vibration, which creates noise. Consider these solutions in your HVAC systems and equipment.

​Shoulder screws

Shoulder screws and vibration mount grommets

Used together to absorb vibrations and dampen noise. Shoulder screws are made of zinc-plated carbon steel, while the grommets are made of neoprene rubber, with an operating temperature range of -40˚C to 50˚C.

​Vibration mount standoffs

Vibration mount standoffs

Not only are vibration mount standoffs ideal for use in the blower motor compartment. The condenser houses HVAC compressor components, which naturally vibrate. The problem with vibrations in all types of HVAC equipment, no matter where the source, is that the sound can carry through ducts, creating an enormous irritation. These vibration mount standoffs act as a buffer by absorbing vibrations. They also help reduce noise. Made of neoprene rubber and steel with an operating temperature range of -40°C to 80°C.

Hook and loop cinch straps with plastic buckle

Also for blower motors:

Hook and loop cinch straps with plastic buckle

Nylon-woven straps mates together easily. Ideal for cables that need to be held together securely, but also need to be released and resealed occasionally for maintenance. Available in widths of 24mm, 28mm and 33mm.
HVAC condenser


HVAC condenser components can also be used in other parts of your design.

​Hook and loop rolls

Hook and loop rolls

Available in rolls that can be cut to the length needed and mated together. Ideal for cables that need to be held together securely, but also need to be released and resealed occasionally. Made of LDPE. Operating temperature range: -17˚C ­­­­– 104˚C. Also ideal for the HVAC’s blower motor. For colour-coding, consider hook and loop cable ties.

​Cable tie mounts – edge mount

Cable tie mounts – edge mount

Provides a strong retention force when attached to the side of the HVAC’s metal panel, allowing a cable tie to be passed through. Nylon 6/6 with a grip material made of 304 stainless steel. Rated UL94 V-2. Adhesive cable tie mounts are another good choice to consider.

​T-Bolt clamps

T-Bolt clamps

T-bolt hose clamps provide a dependable seal on industrial drain-tube assemblies, which are housed just outside the condenser. Especially ideal for any hoses or cables where high vibration occurs, such as generated by industrial HVAC systems. 301 Stainless Steel. For non-industrial HVACs, you might find that plastic hose clamps are better suited to your needs.

HVAC Evaporator coil

Evaporator coil

Your cables will run between panels, so you’ll also need grommets for their protection.

​Standard cable ties

Standard cable ties

Tough, high-quality plastic cable ties are designed with a built-in lock system to prevent accidental removal. This locking cable tie is made of nylon 6/6 and rated UL94 V-2.

HVAC housing

HVAC housing

For the panels that encase residential, commercial and industrial HVAC systems, you’ll need a variety of components.

​3D-Adjustable HVAC hinges

3D-Adjustable HVAC hinges

Make three-dimensional adjustments on large flush-fitting doors. Die-cast zinc alloy. Another excellent choice is a free swinging hinge – leaf hinge, a heavy-duty butt hinge designed for security, with concealed mounting screws that prevent external access to the hinge.

​Functional locking hinge

Functional locking hinge

A hinge and compression lock/latch working as one component, enabling decompression before opening the door. Easy to assemble, it allows for door adjustment for tight sealing to prevent leaks or convenient door removal. Ideal for industrial and commercial building HVAC systems. Nylon with a stainless steel pin.



L-handles key alike, key differ or keyless, in different styles. T-handles also available. For better sealing under vibration conditions, think about using a NEMA-rated adjustable L-handle with compression.

​Cable conduit – PVC-coated metal

Cable conduit – PVC-coated metal

Flexible plastic conduit for cables run power and control wires to HVAC equipment. Supports PVC-coated galvanised steel conduit systems and conduit accessories. High mechanical strength and liquid tight, making it suitable for outdoor use.

​Sealing gaskets

Sealing gaskets

Components of a commercial HVAC system, or other HVAC types, should include sealing gaskets, such as bubble gasket seals. They provide additional seal and noise dampening from vibrations. Also protects against humidity and dirt ingress. Available in EPDM and PVC. You can also use weather stripping tape and gasket tape.

​Recessed handles

Recessed handles

Recessed pull handles come in different styles and snap easily into place. Ideal for safety concerns by avoiding sharp edges. These plastic recessed handles are made of acrylonitrile butadiene styrene (ABS). While ABS can be used outdoors, it will have longer life on an indoor HVAC.

​Blind plastic rivets

Blind plastic rivets

For secure locking without soldering. Also known as clinch rivets, they work with a large range of panel thicknesses. Easy to install by inserting the U-shaped body into the hole and tapping the T-shaped head with a hammer until flush. Available in different styles. Nylon 6/6 with an operating temperature range of -40˚C to 85˚C.

​Anti-vibration mounts – heavy-duty industrial

Anti-vibration mounts – heavy-duty industrial

Commercial and industrial HVAC systems generate vibrations, but you can address the issue with heavy-duty anti-vibration mounts placed on the bottom of the external housing. Their high-strength sandwich-mount construction reduces shock and vibration by up to 80%. The large support plate provides precision levelling and prevents walking or slipping out of position. Made of rubber and steel.

Standard hex nuts – metal

Standard hex nuts – metal

Standard hex nuts are used with anchors, bolts, screws, studs, threaded rods and on any other fastener that has machine screw threads. The hexagonal shape means they’re easy to fasten or, if needed, loosen. Available in mild steel or stainless steel to resist corrosion. To get more friction and prevent the hex nut from loosening, use with single wave spring washers.

​High-bond tape rolls

High-bond tape rolls

High-performance acrylic-foam-core tapes are tamper resistant and ideal for bonding dissimilar metals and performing as mechanical fasteners and replacing welding. Excellent resistance to temperature cycles. Available in 4 colours: clear, white, grey, and black. Clear is ideal for clear acrylic and glass applications. Operating temperature Range: -28˚C to 148˚C.

​Standard grommets

Standard grommets

You’ll need grommets to protect cables passed between compartment panels inside your HVAC. These cable grommets snap in for quick and easy installation. Available in different materials: PVC and a greener alternative, TPE. You can also choose EPDM and thermoplastic rubber cable grommets. You can also consider snub bushing, which are similar to grommets, but add the extra elements of cable strain relief and insulation.

​Cable glands – straight

Cable glands – straight

Also known as strain-relief cord grips, these provide entry for a cable into your HVAC. Available with variations in thread size, colour and mounting thread. Made of nylon. You may also need cable gland locknuts.

Vibration mounts – heavy duty

Vibration mounts – heavy duty

Heavy-duty screw-on vibration mounts are perfect as feet for HVAC system equipment. They absorb shock and reduce noise with high adhesion to the floor. Made of TPE.

​Inspection windows

Inspection windows

Thick frame fits diameter mounting holes to allow viewing of counters, dials, and instruments from the outside. Made of strong, touch polycarbonate.

​Pull handle

Pull handle

Through-hole one-sided pull handle is front mounted with a rectangular grab-style handle. Made of nylon 6, reinforced with 30% glass fibre.

​Panel clamp

Panel clamp

Bridge clamping system available in asymmetrical and symmetrical. Required when complete panel removal is necessary. Made of nylon 6, reinforced with 30% glass fibre with a steel screw.

Download free CADs and try before you buy

Free CADs are available for most solutions. You can also request free samples to ensure the solutions you’ve chosen are exactly what you need. If you’re not quite sure which product will work best for your application, our experts are always happy to advise you. Whatever your requirements, you can depend on fast despatch.

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Email us at sales@essentracomponents.co.uk or speak to one of our experts for further information on the ideal solution for your application 0845 758 5070.

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